Go to the app "Display Settings" and click on this menu button. You can easily customize product options according to your store theme style. Here, You can customize product options form on product page detail like the title of your product options, text color, font size, font family and background, etc.
Follow settings are for:
1. Option Title Settings
a) Title Text
b) Title Font Size
c) Title Padding
d) Title Background Color
e) Title Color
f) Title Border Color
g) Title Style Bold or Normal
2. Option Container Settings
a) Background Color
b) Border Color
c) Padding
d) Space Between Options
e) line Between Options
3. Option Name Settings
a) Font Color
b) Font Style Bold or Normal
c) Display option name position Left or Top
4. Options Values Settings
a) Font Color
b) Spacing left of values
5. Custom CSS Settings